stk500-esm/dist/lib/receiveData.js

A modern, ESM-compatible, TypeScript implementation of the STK500v1 protocol for programming Arduino boards directly from Node.js or the browser.

import Constants from "./constants.js";
const startingBytes = [Constants.Resp_STK_INSYNC];
/**
 * Receives data from a stream, looking for specific starting bytes.
 *
 * @param stream - The read/write stream to receive data from.
 * @param timeout - The maximum time to wait for data, in milliseconds.
 * @param responseLength - The expected length of the response.
 * @returns A promise that resolves with the received data as a Uint8Array.
 * @throws Will throw an error if the timeout is reached or if the received data exceeds the expected length.
 */
export default function receiveData(stream, timeout, responseLength) {
    return new Promise((resolve, reject) => {
        let buffer = new Uint8Array(0);
        let started = false;
        let timeoutId;
        const handleChunk = (data) => {
            if (!started) {
                const startIndex = Array.from(data).findIndex((byte) => startingBytes.includes(byte));
                if (startIndex !== -1) {
                    data = data.subarray(startIndex);
                    started = true;
                }
                else {
                    return; // Skip this chunk if starting byte not found
                }
            }
            buffer = new Uint8Array([...buffer, ...data]);
            if (buffer.length > responseLength) {
                finished(new Error(`Buffer overflow ${buffer.length} > ${responseLength}`));
            }
            else if (buffer.length === responseLength) {
                finished();
            }
        };
        const finished = (err) => {
            if (timeoutId) {
                clearTimeout(timeoutId);
            }
            stream.removeListener("data", handleChunk);
            if (err) {
                reject(err);
            }
            else {
                resolve(buffer);
            }
        };
        if (timeout && timeout > 0) {
            timeoutId = setTimeout(() => {
                finished(new Error(`receiveData timeout after ${timeout}ms`));
            }, timeout);
        }
        stream.on("data", handleChunk);
    });
}